Officers greeted with cheers in the Boston area as they take him away

This still frame from video shows Boston Marathon bombing suspect Dzhokhar Tsarnaev visible through an ambulance after he was captured in Watertown, Mass., on Friday. (AP Photo/Robert Ray)

Photo By Julio Cortez/Wire

A police officer and a woman react to news of the arrest of one of the Boston Marathon bombing suspects, Friday, April 19, 2013, in Boston. Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown, Mass. The 19-year-old college student wanted in the bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Julio Cortez)

Photo By Matt Rourke/Wire

State Police Col. Timothy Alben, accompanied by Massachusetts Governor Deval Patrick, speaks during a news conference, after the arrest of a suspect of the Boston Marathon bombings in Watertown, Mass., Friday, April 19, 2013. A 19-year-old college student wanted in the Boston Marathon bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Matt Rourke)(AP Photo/Matt Rourke)

Photo By Win McNamee/Wire

WASHINGTON, DC - APRIL 19: U.S. President Barack Obama speaks from the White House about the capture of Dzhokhar A. Tsarnaev on April 19, 2013 in Washington, DC. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Win McNamee/Getty Images)

Photo By Kevork Djansezian/Wire

WATERTOWN, MA - APRIL 19: Alcohol, Tobacco and Firearm police relax after enjoying a meal following the apprehension earlier of the second suspect in the Boston Marathon bombing on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Kevork Djansezian/Getty Images)

WATERTOWN, MA - APRIL 19: Alcohol, Tobacco and Firearm police relax with a meal following the apprehension earlier of the second suspect in the Boston Marathon bombing on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Kevork Djansezian/Getty Images)

Photo By Boston Globe/Wire

WATERTOWN, MA - APRIL 19: People celebrate on Mt. Auburn Street. After an intense manhunt and two-hour standoff in Watertown, law enforcement took a person into custody believed to be related to the Boston Marathon bombings. (Photo by Jonathan Wiggs/The Boston Globe via Getty Images)

Photo By Kayana Szymczak/Wire

BOSTON - APRIL 19: An estimated 200 people pour onto Hemingway Street in the Fenway neighborhood to celebrate after the announcement earlier of the capture of the second Boston Martathon bombing suspect celebrate April 19, 2013 in Boston, Massachusetts. A manhunt for Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The bombing killed three people and wounded at least 170. (Photo by Kayana Szymczak/Getty Images)

Photo By Kayana Szymczak/Wire

BOSTON - APRIL 19: A few of the estimated 200 people who poured onto Hemingway Street in the Fenway neighborhood to celebrate after the announcement earlier of the capture of the second Boston Martathon bombing suspect celebrate April 19, 2013 in Boston, Massachusetts. A manhunt for Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The bombing killed three people and wounded at least 170. (Photo by Kayana Szymczak/Getty Images)

Photo By Boston Globe/Wire

WATERTOWN, MA - APRIL 19: SWAT team members exit Franklin Street in Watertown with visible relief on their faces. After an intense manhunt and two-hour standoff in Watertown, law enforcement took a person into custody believed to be related to the Boston Marathon bombings. (Photo by Barry Chin/The Boston Globe via Getty Images)

Photo By Boston Globe/Wire

WATERTOWN, MA - APRIL 19: On Arsenal Street, Louise Hunter and others cheer on police on leaving the scene. After an intense manhunt and two-hour standoff in Watertown, law enforcement took a person into custody believed to be related to the Boston Marathon bombings. (Photo by Bill Greene/The Boston Globe via Getty Images)

Photo By Boston Globe/Wire

BOSTON - APRIL 19: After the second suspect was captured, people came to the barricades at the corner of Boylston and Hereford Streets near the Marathon Finish line to celebrate and reflect. A couple looks at a device as the woman carries an American flag. (Photo by Jim Davis/The Boston Globe via Getty Images)

Photo By Julio Cortez/Wire

Joseph Eli Libby, 20, of Boston, carries a flag near a makeshift memorial on Boylston Street, near the finish line of the Boston Marathon, Friday, April 19, 2013, in Boston. Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown, Mass. The 19-year-old college student wanted in the bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Julio Cortez)

Photo By Wire

Mimi de Quesada, of Watertown, Mass., reacts while standing by her home in the wake of the sound of shots fired in Watertown, Mass., Friday, April 19, 2013, as a massive search continued for one of two suspects in the Boston Marathon bombings. De Quesada said she had just come out to enjoy the day when the shots rang out about two blocks form her home. A second suspect died in the early morning hours after an encounter with law enforcement. (AP Photo/Craig Ruttle)

Photo By Jared Wickerham/Wire

Many different law enforcement agencies descend on an area around Franklin Street on April 19, 2013 in Watertown, Massachusetts. After a car chase and shootout with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.

Photo By TIMOTHY A. CLARY/Wire

Residents embrace prior to the capture of the second of two suspects wanted in the Boston Marathon bombings April 19, 2013 in Watertown, Massachusetts. Thousands of heavily armed police staged an intense manhunt for a Chechen teenager suspected in the Boston marathon bombings with his brother, who was killed in a shootout. Dzhokhar Tsarnaev, 19, defied the massive force after his 26-year-old brother Tamerlan was shot and suffered critical injuries from explosives believed to have been strapped to his body. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/Getty Images)

Photo By TIMOTHY A. CLARY/Wire

Residents await the capture of the second of two suspects wanted in the Boston Marathon bombings April 19, 2013 in Watertown, Massachusetts. Thousands of heavily armed police staged an intense manhunt for a Chechen teenager suspected in the Boston marathon bombings with his brother, who was killed in a shootout. Dzhokhar Tsarnaev, 19, defied the massive force after his 26-year-old brother Tamerlan was shot and suffered critical injuries from explosives believed to have been strapped to his body. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/Getty Images)

Photo By Jared Wickerham/Wire

WATERTOWN, MA - APRIL 19: Spectators clap and cheer while law enforcement members leave the scene near Franklin Street on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Jared Wickerham/Getty Images)

Photo By Jared Wickerham/Wire

WATERTOWN, MA - APRIL 19: Spectators clap and cheer while law enforcement members leave the scene near Franklin Street on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Jared Wickerham/Getty Images)

Photo By Jared Wickerham/Wire

WATERTOWN, MA - APRIL 19: Two police officers laugh while securing the area around Franklin Street on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Jared Wickerham/Getty Images)

Photo By Spencer Platt/Wire

WATERTOWN, MA - APRIL 19: Women cheer police as they exit Franklin Street after 19-year-old bombing suspect Dzhokhar A. Tsarnaev was apprehended on April 19, 2013 in Watertown, Massachusetts. A manhunt for Boston Marathon bombing suspect Tsarnaev ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.(Photo by Spencer Platt/Getty Images)

Photo By Mario Tama/Wire

WATERTOWN, MA - APRIL 19: A SWAT team member is followed by reporters and a celebrating crowd after the successful operation to capture 19-year-old bombing suspect Dzhokhar A. Tsarnaev on April 19, 2013 in Watertown, Massachusetts. A manhunt for a suspect in the Boston Marathon bombing, Dzhokhar A. Tsarnaev, 19, ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170. (Photo by Mario Tama/Getty Images)

Photo By Spencer Platt/Wire

WATERTOWN, MA - APRIL 19: Members of a police S.W.A.T. team exit Franklin Street moments after 19-year-old bombing suspect Dzhokhar A. Tsarnaev was apprehended on April 19, 2013 in Watertown, Massachusetts. A manhunt for Boston Marathon bombing suspect Tsarnaev ended this evening with his capture on a boat parked on a residential property in Watertown, Massachusetts. His brother Tamerlan Tsarnaev, 26, the other suspect, was shot and killed by police early this morning after a car chase and shootout with police. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.(Photo by Spencer Platt/Getty Images)

Photo By Robert Ray/Wire

This still frame from video shows Boston Marathon bombing suspect Dzhokhar Tsarnaev visible through an ambulance after he was captured in Watertown, Mass., Friday, April 19, 2013. A 19-year-old college student wanted in the Boston Marathon bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Robert Ray)

Photo By Jared Wickerham/Getty Images

Many different law enforcement agencies descend on an area around Franklin Street on April 19, 2013 in Watertown, Massachusetts. After a car chase and shootout with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.

Photo By Spencer Platt/Getty Images

Police converge near the scene where it was believed 19-year-old bombing suspect Dzhokhar A. Tsarnaev is in hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old suspect Dzhokhar A. Tsarnaev. The two men, reportedly of Chechen origin, are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Jared Wickerham/Getty Images

Many different law enforcement agencies descend on an area around Franklin Street on April 19, 2013 in Watertown, Massachusetts. After a car chase and shootout with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.

Photo By Darren McCollester/Wire

WATERTOWN, MA - APRIL 19: Residents flee from an area where a suspect is hiding on Franklin St., on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170. (Photo by Darren McCollester/Getty Images)

Photo By Darren McCollester/Wire

WATERTOWN, MA - APRIL 19: An officer carries a child away from an area where a suspect is hiding on Franklin St., on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170. (Photo by Darren McCollester/Getty Images)

Photo By Darren McCollester/Getty Images

Law enforcement evacuate people near to where a suspect is hiding on Franklin St., April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Spencer Platt/Getty Images

Members of a police S.W.A.T. team run to the area where it was believed 19-year-old bombing suspect Dzhokhar A. Tsarnaev is hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police last night, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old suspect Dzhokhar A. Tsarnaev. The two men, reportedly of Chechen of origin, are suspects in the bombings at the Boston Marathon on April 15 that killed three people and wounded at least 170.

Photo By Darren McCollester/Getty Images

Law enforcement evacuate people away from an area reportedly where a suspect is hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Spencer Platt/Getty Images

Family members who fled the scene where it was believed 19-year-old bombing suspect Dzhokhar A. Tsarnaev is in hiding are comforted on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old suspect Dzhokhar A. Tsarnaev. The two men, reportedly of Chechen origin, are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Darren McCollester/Getty Images

Law enforcement approach an area reportedly where a suspect is hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Darren McCollester/Getty Images

Law enforcement approach an area reportedly where a suspect is hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Mario Tama/Getty Images

Resident Rosie Meyer, who said she heard gunshots, reacts while watching police respond on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old suspect Dzhokhar A. Tsarnaev. The two men, reportedly Chechen of origin, are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Darren McCollester/Getty Images

Law enforcement approach an area reportedly where a suspect is hiding on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Darren McCollester/Wire

WATERTOWN, MA - APRIL 19: Massachusetts State Police Colonel Timothy Alben addresses the media April 19, 2013 in Watertown, Massachusetts. The lockdown of Watertown has been lifted after last nights shootout between police and the two Boston Marathon bombing suspects. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170. (Photo by Darren McCollester/Getty Images)

Photo By Wire

A news reporter waits for her cue as police guard the apartment building where the sister of the Boston marathon bombing suspects is believed to live, Friday, April 19, 2013, in West New York, N.J. Federal investigators had removed items from the house earlier in the day, although there is no indication that the sister was involved in the bombing. (AP Photo/John Minchillo)

Photo By Spencer Platt/Getty Images

Members of a police S.W.A.T. team search through a neighborhood in Watertown as they search for 19-year-old bombing suspect Dzhokhar A. Tsarnaev on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Spencer Platt/Getty Images

Members of a police SWAT team conduct a door-to-door search for 19-year-old Boston Marathon bombing suspect Dzhokhar A. Tsarnaev on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Mario Tama/Getty Images

U.S. military helicopters fly over mobile television dishes during the search for 19-year-old Boston Marathon bombing suspect Dzhokhar A. Tsarnaev on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old Dzhokhar A. Tsarnaev. The two men are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Getty Images

A police SWAT team search houses for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. Thousands of heavily armed police staged an intense manhunt Friday for a Chechen teenager suspected in the Boston marathon bombings with his brother, who was killed in a shootout. Dzhokhar Tsarnaev, 19, defied the massive force after his 26-year-old brother Tamerlan was shot and suffered critical injuries from explosives believed to have been strapped to his body. AFP PHOTO / TIMOTHY A. CLARY

Photo By Associated Press

In this Feb. 17, 2010, photo, Tamerlan Tsarnaev, left, accepts the trophy for winning the 2010 New England Golden Gloves Championship from Dr. Joseph Downes, right, in Lowell, Mass. Tsarnaev, 26, who had been known to the FBI as Suspect No. 1 in the Boston Marathon Explosions and was seen in surveillance footage in a black baseball cap, was killed overnight on Friday, April 19, 2013, officials said. (AP Photo/The Lowell Sun, Julia Malakie)

Photo By Boston Globe/Getty Images

Police action at 17 Willow Avenue during the ongoing manhunt for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week. Watertown is on lockdown following a chase and shootout in the area last night.

Photo By Boston Globe/Getty Images

SWAT search on Nichols Avenue at the corner of Dexter during the ongoing manhunt for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week. Watertown is on lockdown following a chase and shootout in the area last night.

Photo By Boston Globe/Getty Images

WATERTOWN, MA - APRIL 19: SWAT teams moved into position at the intersection of Nichols Avenue and Melendy Avenue in Watertown while searching for one of the two marathon bombing suspects.

Photo By Boston Globe/Getty Images

State Police officers stop a car at the intersection of Carver Road and Belmont Street in Watertown while searching for one of the two suspects in the terrorist bombing of the 117th Boston Marathon earlier this week.

Photo By Lucas Oleniuk/Getty Images

Tamerlan and Dzhokhar Tsarnaev's aunt Maret Tsarnaeva spoke to Toronto media in the lobby of her Etobicoke apartment building April 19, 1013. Dzhokhar Tsarnaev is the suspect at large wanted in connection with the Boston bombings. Tamerlan was killed by Boston police in a shootout.

Photo By STAN HONDA/Getty Images

Massachusetts Governor Deval Patrick (at microphone) speaks to the media with Boston Mayor Thomas Menino (L, in wheelchair), Boston Police Commissioner Ed Davis (L, behind Menino) and Watertown Chief of Police Edward P. Deveau (R, behind Patrick) at the Watertown Mall as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts.

Photo By Boston Globe/Getty Images

SWAT teams searched homes along Winsor Avenue in Watertown while searching for one of the two suspects in the terrorist bombing of the 117th Boston Marathon earlier this week.

Photo By Boston Globe/Getty Images

SWAT teams searched homes along Winsor Avenue in Watertown while searching for one of the two suspects in the terrorist bombing of the 117th Boston Marathon earlier this week.

Photo By STAN HONDA/Getty Images

A National Guard helicopter prepares to land behind the Watertown Mall as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. Thousands of heavily armed police staged an intense manhunt Friday for a Chechen teenager suspected in the Boston marathon bombings with his brother, who was killed in a shootout. Dzhokhar Tsarnaev, 19, defied the massive force after his 26-year-old brother Tamerlan was shot and suffered critical injuries from explosives believed to have been strapped to his body. AFP PHOTO/Stan HONDA

Photo By Associated Press

A barefooted woman runs for cover as police surround a home while searching for a suspect in the Boston Marathon bombings in Watertown, Mass., Friday, April 19, 2013. Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during a getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist. (AP Photo/Charles Krupa)

Photo By Mario Tama/Getty Images

Members of a SWAT team search for 19-year-old bombing suspect Dzhokhar A. Tsarnaev on April 19, 2013 in Watertown, Massachusetts. After a car chase and shoot out with police, one suspect in the Boston Marathon bombing, Tamerlan Tsarnaev, 26, was shot and killed by police early morning April 19, and a manhunt is underway for his brother and second suspect, 19-year-old suspect Dzhokhar A. Tsarnaev. The two men, reportedly Chechen of origin, are suspects in the bombings at the Boston Marathon on April 15, that killed three people and wounded at least 170.

Photo By Associated Press

Ruslan Tsarni, the uncle of the Boston Marathon bombing suspect, speaks with the media outside his home in Montgomery Village in Md. Friday, April, 19, 2013. Tsarni urged his nephew to turn himself in.

Photo By Boston Globe/Getty Images

SWAT teams searched homes along Winsor Avenue in Watertown while searching for one of the two suspects in the terrorist bombing of the 117th Boston Marathon earlier this week.

Photo By Associated Press

A member of the Cambridge police bomb squad, right, deploys a robot on Norfolk Street during a search for searching a suspect in the Boston Marathon bombings in Cambridge, Mass., Friday, April 19, 2013. Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during a getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist.

Photo By Associated Press

A police officer evacuates a shoeless man holding a child as members of law enforcement conduct a search for a suspect in the Boston Marathon bombings, Friday, April 19, 2013, in Watertown, Mass. The two suspects in the Boston Marathon bombing killed an MIT police officer and hurled explosives at police in a car chase and gun battle overnight that left one of them dead and his brother on the loose, authorities said Friday as thousands of officers swarmed the streets in a manhunt that all but paralyzed the Boston area.

Photo By Boston Globe/Getty Images

SWAT teams moved into position at the intersection of Nichols Avenue and Melendy Avenue in Watertown while searching for one of the two marathon bombing suspects.

Photo By Boston Globe/Getty Images

SWAT teams moved into position at the intersection of Nichols Avenue and Melendy Avenue in Watertown while searching for one of the two marathon bombing suspects.

Photo By Michael Dwyer/Getty Images

FBI and local law enforcement personnel continue their search for a suspect in the Boston Marathon bombings on Norfolk Street in Cambridge, Mass., Friday, April 19, 2013. Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during a getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist.

Photo By Uncredited/Getty Images

This undated photo provided by the Middlesex District Attorney's Office shows Massachusetts Institute of Technology Police Officer Sean Collier, 26, of Somerville, Mass., who was shot to death Thursday, April 18, 2013 on the school campus in Cambridge, Mass. Authorities said surveillance tape recorded late Thursday showed one of the Boston Marathon bombing suspects during a robbery of a nearby convenience store before Collier was shot to death while responding to a report of a disturbance.

Photo By Michael Dwyer/Getty Images

A resident evacuates as police go door-to-door on Norfolk Street in search of a suspect in the Boston Marathon bombings in Cambridge, Mass., Friday, April 19, 2013. Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during a getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist.

Photo By Boston Globe/Getty Images

State Police search for second suspect on Mount Auburn Street near Watertown Square. A manhunt is underway for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week.

Photo By Darren McCollester/Getty Images

Federal agents descend on the home of a suspect-at-large in the Boston Marathon bombing and nearby Watertown shooting, on Norfolk Street April 19, 2013 in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Boston Globe/Getty Images

The Boston area is under lockdown as as a manhunt is underway for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week. The Mass. Avenue bridge has only a few pedestrians crossing.

Photo By Uncredited/Getty Images

This undated photo provided by the vkontakte website shows Dzhokhar Tsarnaev. Dzhokhar Tsarnaev has been on the run, described as "armed and dangerous" and suspected of the Boston Marathon bombing. His brother, Tamerlan, was killed during a violent police chase. The two ethnic Chechen brothers came from Dagestan, a Russian republic bordering the province of Chechnya.

Photo By Associated Press

This Monday, April 15, 2013, shows a man who was dubbed Suspect No. 2 in the Boston Marathon bombings by law enforcement, in the upper center of the frame, wearing a white baseball cap, walking away from the scene of the explosions. The FBI identified him as 19-year-old college student Dzhokhar Tsarnaev, who along with his brother Tamerlan, 26, previously known as Suspect No. 1, killed an MIT police officer, severely wounded another lawman and hurled explosives at police in a car chase and gun battle during a night of violence, early Friday, April 19, 2013. Tamerlan Tsarnaev was killed overnight, officials said, while his brother Dzhokhar remains at large.

Photo By Charles Krupa

Police in tactical gear arrive on an armored police vehicle as they surround an apartment building while looking for a suspect in the Boston Marathon bombings in Watertown, Mass., Friday, April 19, 2013. The bombs that blew up seconds apart near the finish line of the Boston Marathon left the streets spattered with blood and glass, and gaping questions of who chose to attack and why.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: A Massachusetts State Police officer checks the bag of a cyclist during heightened security on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: SWAT team members search for one remaining suspect at a residential building as a man looks out from a window on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By STAN HONDA/Getty Images

A dog sniffs equipment before Massachusetts Governor Deval Patrick spoke to the media at a shopping mall on the perimeter of a locked down area as a search for the second of two suspects wanted in the Boston Marathon bombings takes place on April 19, 2013 in Watertown, Massachusetts. AFP PHOTO/Stan HONDA

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Members of the FBI, State Police, Boston Police, Cambridge Police, and other law enforcement agencies, put up police tape securing a perimeter in front of a woman being questioned by the FBI on April 19, 2013 near the home of suspect #2 on Norfolk Street in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: A woman reacts while being questioned by the FBI and other law enforcement agencies on April 19, 2013 near the home of suspect #2 on Norfolk Street in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Residents of an apartment building watch as members of the FBI, State Police, Boston Police, Cambridge Police, and other law enforcement agencies, survey the perimeter on April 19, 2013 near the home of suspect #2 on Norfolk Street in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Boston Globe/Getty Images

Katia Costa looks out her window at all the police activity below on the street at Nichols Avenue during the ongoing manhunt for a suspect in the terrorist bombing of the 117th Boston Marathon earlier this week. Watertown is on lockdown following a chase and shootout in the area last night.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Members of the FBI, State Police, Boston Police, Cambridge Police, and other law enforcement agencies, survey the perimeter on April 19, 2013 near the home of suspect #2 on Norfolk Street in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: A woman reacts while being questioned by the Cambridge Police and other law enforcement agencies on April 19, 2013 near the home of suspect #2 on Norfolk Street in Cambridge, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By AP

Police officers walk near a crime scene Friday, April 19, 2013, in Watertown, Mass. A tense night of police activity that left a university officer dead on campus just days after the Boston Marathon bombings and amid a hunt for two suspects caused officers to converge on a neighborhood outside Boston, where residents heard gunfire and explosions.

Photo By Darren McCollester/Getty Images

WATERTOWN, MA - APRIL 19: Police descend on School and Walnut Street chasing possible suspects on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Darren McCollester/Getty Images

WATERTOWN, MA - APRIL 19: Police descend on School and Walnut Street chasing possible suspects on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: A police officer with gun drawn and flashlight searches for a suspect on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By STAN HONDA/Getty Images

A Boston police officer mans a closed off neighborhood as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. Police killed one of the suspected Boston marathon bombing suspects in a shootout early today and pursued a chaotic deadly street-to-street manhunt for his accomplice, officials said. AFP PHOTO/Stan HONDA

Photo By STAN HONDA/Getty Images

A Boston police officer allows police vehicles out of a closed area as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. Police killed one of the suspected Boston marathon bombing suspects in a shootout early today and pursued a chaotic deadly street-to-street manhunt for his accomplice, officials said.
AFP PHOTO/Stan HONDA

Photo By STAN HONDA/Getty Images

A Boston police officer allows a police vehicle into a closed area as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. Police killed one of the suspected Boston marathon bombing suspects in a shootout early today and pursued a chaotic deadly street-to-street manhunt for his accomplice, officials said.
AFP PHOTO/Stan HONDA

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Boston Police mobilize in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Boston Police mobilize in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Boston Police Commissioner Edward Davis speaks during a media briefing in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Boston Police Commissioner Edward Davis speaks during a media briefing in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Darren McCollester/Getty Images

WATERTOWN, MA - APRIL 19: Police convene on School and Walnut Street on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Military Police arrive in armoured vehicles at the parking lot of the Arsenal Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: A Watertown Police official speaks during a media briefing in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Jared Wickerham/Getty Images

WATERTOWN, MA - APRIL 19: Boston Police mobilize in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Darren McCollester/Getty Images

WATERTOWN, MA - APRIL 19: Police walk down School and Walnut Street on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Darren McCollester/Getty Images

WATERTOWN, MA - APRIL 19: Police convene on School and Walnut Street on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: Onlookers take pictures as they watch from windows while SWAT team members search for one remaining suspect at a neighboring apartment building on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: SWAT team members search for one remaining suspect at a residential building on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By Mario Tama/Getty Images

WATERTOWN, MA - APRIL 19: SWAT team members aim their guns as they search for one remaining suspect at an apartment building on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another - believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs.

Photo By STAN HONDA/Getty Images

Colonel Timothy Albens (C, at microphone), Massachusetts State Police, with Massachusetts Governor Deval Patrick (R) and Boston Police Commissioner Ed Davis (L) speaks to the media at a shopping mall on the perimeter of a locked down area as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. AFP PHOTO/Stan HONDA

Photo By STAN HONDA/Getty Images

Massachusetts Governor Deval Patrick (L) speaks to the media at a shopping mall on the perimeter of a locked down area as a search for the second of two suspects wanted in the Boston Marathon bombings takes place April 19, 2013 in Watertown, Massachusetts. AFP PHOTO/Stan HONDA

WATERTOWN, Mass. — Lifting days of anxiety for a city and a nation on edge, police captured the surviving Boston Marathon bombing suspect, found bloodied in a backyard boat Friday night less than 24 hours after a wild car chase and gun battle that left his older brother dead and Boston and its suburbs sealed in an extraordinary dragnet.

"CAPTURED!!!" police added later. "The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody."

During a long night of violence Thursday and into Friday, brothers Dzhokhar and Tamerlan Tsarnaev killed an MIT police officer, severely wounded another lawman and hurled explosives at police in a desperate getaway attempt, authorities said.

Late Friday, less than an hour after authorities said the search for Dzhokhar had proved fruitless, they tracked down the 19-year-old college student holed up in the boat, weakened by a gunshot wound after fleeing on foot from the overnight shootout with police that left 200 spent rounds behind.

He was hospitalized in serious condition, unable to be questioned about his motives.

Tamerlan Tsarnaev, 26, died in the shootout early in the day. At one point, he was run over by his younger brother in a car as he lay wounded, according to investigators.

The violent endgame unfolded four days after the bombing and just a day after the FBI released surveillance-camera images of two young men suspected of planting the pressure-cooker explosives that ripped through the crowd at the marathon finish line, killing three people and wounding more than 180.

The two men were identified by authorities and relatives as ethnic Chechens from southern Russia who had been in the U.S. for about a decade and were believed to be living in Cambridge, just outside Boston. But investigators gave no details on the motive for the attack.

President Barack Obama said the nation owes a debt of gratitude to law enforcement officials and the people of Boston for their help in the search. But he said there are many unanswered questions about the Boston bombings, including whether the two men had help from others. He urged people not to rush judgment about their motivations.

The breakthrough came when a man in a Watertown neighborhood saw blood on a boat parked in a yard and pulled back the tarp to see a man covered in blood, authorities said. The resident called 911 and when police arrived, they tried to talk the suspect into getting out of the boat, said Boston Police Commissioner Ed Davis.

"He was not communicative," Davis said.

Instead, he said, there was an exchange of gunfire — the final volley of one of the biggest manhunts in American history.

Watertown residents who had been told in the morning to stay inside behind locked doors poured out of their homes and lined the streets to cheer police vehicles as they rolled away from the scene.

Celebratory bells rang from a church tower. Teenagers waved American flags. Drivers honked. Every time an emergency vehicle went by, people cheered loudly.

"They finally caught the jerk," said nurse Cindy Boyle. "It was scary. It was tense."

Police said three other people were taken into custody for questioning at an off-campus housing complex at the University of the Massachusetts at Dartmouth where the younger man may have lived.

"Tonight, our family applauds the entire law enforcement community for a job well done, and trust that our justice system will now do its job," said the family of 8-year-old Martin Richard, who died in the bombing.

The FBI was swamped with tips — 300,000 per minute — after the release of the surveillance-camera photos, but what role those played in the overnight clash was unclear. State Police spokesman Dave Procopio said police realized they were dealing with the bombing suspects based on what the two men told a carjacking victim during their night of crime.

The search by thousands of law enforcement officers all but paralyzed the Boston area for much of the day. Officials shut down all mass transit, including Amtrak trains to New York, advised businesses not to open, and warned close to 1 million people in the entire city and some of its suburbs to unlock their doors only for uniformed police.

Around midday, the suspects' uncle, Ruslan Tsarni of Montgomery Village, Md., pleaded on television: "Dzhokhar, if you are alive, turn yourself in and ask for forgiveness."

Until the younger man's capture, it was looking like a grim day for police. As night fell, they announced that they were scaling back the hunt and lifting the stay-indoors order across Boston and some of its suburbs because they had come up empty-handed.

But then the break came and within a couple of hours, the four-day ordeal was over. Dzhokhar Tsarnaev was captured about a mile from the site of the shootout that killed his brother.

Chechnya has been the scene of two wars between Russian forces and separatists since 1994, in which tens of thousands were killed in heavy Russian bombing. That spawned an Islamic insurgency that has carried out deadly bombings in Russia and the region, although not in the West.

The older brother had strong political views about the United States, said Albrecht Ammon, 18, a downstairs-apartment neighbor in Cambridge. Ammon quoted Tsarnaev as saying that the U.S. uses the Bible as "an excuse for invading other countries."

Also, the FBI interviewed the older brother at the request of a foreign government in 2011, and nothing derogatory was found, according to a federal law enforcement official who was not authorized to discuss the case publicly and spoke on condition of anonymity.

The official did not identify the foreign country or say why it made the request.

Authorities said the man dubbed Suspect No. 1 — the one in sunglasses and a dark baseball cap in the surveillance-camera pictures — was Tamerlan Tsarnaev, while Suspect No. 2, the one in a white baseball cap worn backward, was his younger brother.

Exactly how the long night of crime began was unclear. But police said the brothers carjacked a man in a Mercedes-Benz in Cambridge, just across the Charles River from Boston, then released him unharmed at a gas station.

They also shot to death a Massachusetts Institute of Technology police officer, 26-year-old Sean Collier, while he was responding to a report of a disturbance, investigators said.

The search for the Mercedes led to a chase that ended in Watertown, where authorities said the suspects threw explosive devices from the car and exchanged gunfire with police. A transit police officer, 33-year-old Richard Donohue, was shot and critically wounded, authorities said.

Dzhokhar Tsarnaev somehow slipped away. He ran over his already wounded brother as he fled, according to two law enforcement officials who spoke on condition of anonymity because they were not authorized to discuss the investigation. At some point, he abandoned his car and ran away.

Tamerlan Tsarnaev died at a Boston hospital after suffering what doctors said were multiple gunshot wounds and a possible blast injury.

The brothers had built an arsenal of pipe bombs, grenades and improvised explosive devices and used some of the weapons in trying to make their getaway, said Rep. Dutch Ruppersberger, D-Md., a member of the House Intelligence Committee.

Watertown resident Kayla Dipaolo said she was woken up overnight by gunfire and a large explosion that sounded "like it was right next to my head ... and shook the whole house."

She said she was looking at the front door when a bullet came through the side paneling. SWAT team officers were running all over her yard, she said.

"It was very scary," she said. "There are two bullet holes in the side of my house, and by the front door there is another."

Tamerlan Tsarnaev had studied accounting as a part-time student at Bunker Hill Community College in Boston for three semesters from 2006 to 2008, the school said.

Dzhokhar Tsarnaev was registered as a student at the University of Massachusetts Dartmouth. Students said he was on campus this week after the Boston Marathon bombing. The campus closed down Friday along with colleges around the Boston area.

The men's father, Anzor Tsarnaev, said in a telephone interview with AP from the Russian city of Makhachkala that his younger son, Dzhokhar, is "a true angel." He said his son was studying medicine.

"He is such an intelligent boy," the father said. "We expected him to come on holidays here."

The city of Cambridge announced two years ago that it had awarded a $2,500 scholarship to him. At the time, he was a senior at Cambridge Rindge & Latin School, a highly regarded public school whose alumni include Matt Damon, Ben Affleck and NBA Hall of Famer Patrick Ewing.

Tsarni, the men's uncle, said the brothers traveled here together from Russia. He called his nephews "losers" and said they had struggled to settle in the U.S. and ended up "thereby just hating everyone."